The present invention relates to coilable rules and more particularly to top reading rules with improved measuring indicia visible in the top reading window to facilitate the determination of the direction of numeric increase.
Top reading rules are gaining considerable acceptance because of ease in measuring dimensions between the outer end of the blade and the rearward end of the rule casing, while at the same time permitting use of the extended length of the blade for measuring distances therealong. Depending upon the size of the casing for the rule, the window in the top wall will have a finite length, particularly if one wishes to maintain substantial strength in the casing at reasonable cost. As a result in some top reading rules the window length will be such that only one number will be visible though the window and the user will have difficulty in recongizing whether an intermediate graduation is to be added to the visible number or whether the last lower number is at appropriate integer to use in determining the effective measured length. Moreover, frequently the indicia provided on the blade which are to be read through the window do not permit facile viewing from a number of directions.
It is the object of the present invention to provide a novel top reading rule wherein the blade is imprinted or otherwise provided with indicia facilitate user orientation as to the direction increasing dimension or numeric value on the surface of the rule blade visible through the top reading window.
It is also the object to provide such a top reading rule wherein the user's eye is caused to focus on directional pointers readily orienting the user as to the direction of increasing numbers on the top reading rule scale.
Another object is to provide such a rule in which the measuring indicia may be readily viewed from a number of directions and the user readily oriented as the direction of the blade indicia representing increasing numeric values.